GridLab WP-2Cactus GAT (CGAT)

Ed Seidel, AEI & LSU

Co-chair, GGF Apps RG, Gridstart Apps TWG

Gabrielle Allen, Robert Engel, Tom Goodale, *Thomas Radke

Others from WP-1

WP2

Vision

Goal: enable all Cactus apps to use GAT for Grid scenarios.

Very important WP, prototyped in first year, now being fully developed as GAT implementation in first full release

Cactus (http://www.cactuscode.org)Leading application framework used by dozens of groups in astrophysics (EU Network), climate, CFD, numerical relativity, bio-informaticsUsed for many years for in (pre)Grid environments, and is commonly deployed for demonstrations of the use of the Grid Previously used hand-crafted Cactus modules, ad-hoc mechanisms, relying on the authors' extensive experience of Grid computing

The CGAT work aims to replace this using functionality available through the GAT APIExemplar: modules for other Cactus apps, worked example for others

WP2

Dynamic Grid Computing

Migration: “Cactus Worm” demonstrated SC00Launch JobRun awhile, write checkpointMigrate itself to next siteRegister new location to User tracks/steersProof of concept, but dirty hackCreated our community!

Spawning: SC01User invokes “Spawner”Analysis tasks outsourcedGlobus enabled login, data transferIt worked!

WP2

WP2

CGAT

Conceptual View

Thorn

Thorn

Thorn

Thorn

Thorn

CGAT consists of a set of “thorns”, linked to GAT Engine, which provide services to Cactus applications. The vast majority of Cactus thorns will be unaware of the CGAT or GAT.

Cactus FleshGAT

GridLabService GridLab

Service

Application Thorns

WP2

CGAT Functionality

Ability to remote trigger app checkpoint, retrieve checkpoint file, and stage it to a new hostProvide performance and other data to external applications using GAT monitoring infrastructure.Export list of application-created files via GAT advert and/or replica functionality, through generic advertising serviceQuery information about the current machine, such as cache size, memory size, size of file-systems, name of machine.Spawning of tasks, e.g. for task farming, monitoring status.Automated/triggered announcement of app events, such as app startup, reaching particular iteration, termination, etc.Etc: Working with app communities to determine need: GGF, Gridstart TWG, other projects

WP2

Status

SC03: thorns were written with prototype GAT Engine to enable the GridLab migration scenario:

Remote monitoring of the status of the running Cactus applicationTriggering of Cactus checkpointingAdvertisement of Cactus checkpointing data

Now: thorns converted to use the new GAT implementation and the specified GAT API

Will be demonstrated at this review and at GGF this week

Any application in Cactus can take advantage of this without any other modification

E.g., Black Holes on regular meshes, CFD on unstructured meshes (planned), ocean-atmosphere modeling

WP2

Some Specifics

Gridmake: https://sourceforge.net/projects/gridmake/Distribute/compile source code on an arbitrary number of machinesNeeded for GridLab migration, Cactus remote testing, creation of executables for MPI simulations across multiple machinesGood for codes with configurable make environments, machine configuration scripts, use of CVS etc.Developed using public key infrastructure, soon as a grid serviceTo be incorporated as a GridSphere portlet

Thorn_cgatInitializes GATRegisters that this is checkpointable app with grmsReceives requests from grms (or any broker)Steers cactus parameter to initiate checkpointReports on success of checkpoint

WP2

Near Future

Review current thorns, make production versions, distributeAdd remaining functionalityWork with AEI/LSU numerical relativity group

ensure correct functionality train on use of CGAT infrastructure develop task farming infrastructure for physics surveys

Deploy across GridLab testbed and LSU-AEI-KISTI GridWork with other Cactus app groups in astrophysics, climate, CFD, bioinformatics, others; NSF and DOE projects in USNew, experienced personnel just added now that GAT ready